Practical Mechanical Engineering: A Guide to Mechanisms, Materials, Motors, and Machine Design for People Who Build Things

You already know how to build it. What you don't know is whether it will hold. You've been here. The bracket you welded looked plenty strong - until it bowed under half the load you expected. The mount wobbled at speed. The arm let go, and someone was standing close enough that you still think about it. So you did what everyone does. You made the next one thicker. Then heavier. Then you over-built the whole machine "just to be safe" - burning material, weight, money and a weekend on a guess. And you're still guessing, because nothing you did told you why the first one failed. Here's the uncomfortable part: it was knowable. Not to three decimal places. But well enough to have chosen a thicker wall, a different alloy, or a bolt one size up - in about ten minutes, with a calculator you already own. By the end of this book you will be able to: - Look at a part you haven't made yet and say what load it holds - before you cut metal.- Stop over-building. Most people waste material because they can't calculate a factor of safety, so they guess high and pay for it in weight and cost.- Find out why the bolt you tightened "good and tight" is the first one to work loose - and the number that actually clamps a joint together (Chapter 5).- Size a motor on torque and speed instead of buying twice: once too small, then too expensive.- Work out a gear ratio, a belt drive and a full drivetrain that survives the load you actually have - not the load the catalogue assumed.- Understand why your press fit slid in too easily, and use the table that stops it happening again (Chapter 15).- Know the moment a job has left DIY territory - this book marks where it stops and says plainly when you need a licensed engineer. Before you decide: "The maths will lose me." No calculus. Algebra and a little trigonometry, and that's the whole prerequisite. Every worked example runs from problem statement to a boxed answer with units tracked at each step, and every practice problem is worked in full in the key - not just answered. "I've bought engineering books before and they sat on the shelf." Those were written for someone doing a degree. This was written for someone with a project on the bench right now: a winch mount you actually size, gear ratios in a drill you've held, bearings in a go-kart axle. "I'll just look it up when I need it." You already do. That's why the bracket bent.Scroll up and click Add to Cart - and build the next one knowing, not hoping.